Field of the Invention
The present invention relates to a radiation imaging apparatus and a radiation imaging system.
Description of the Related Art
A portable radiation imaging apparatus called an electronic cassette has been put into practice. When the portable radiation imaging apparatus is dropped, the resulting impact on the radiation imaging apparatus may break or deform the housing of the radiation imaging apparatus. Various countermeasures against such breakage or deformation have been proposed. Japanese Patent No. 4248940 proposes a technique of forming a housing by using an outer shell and an inner shell and filling the space between the outer shell and the inner shell with a shock absorber. Japanese Patent Laid-Open No. 2013-257198 proposes a technique of chamfering the corners of a housing and attaching detachable shock absorbers to the chamfered surfaces.
The outer surface of the housing disclosed in Japanese Patent No. 4248940 is formed from only an outer shell. When the outer shell is formed from a material having a high elastic modulus, it is possible to reduce the deformation of the overall housing when it is dropped. However, a stress concentrates on the outer shell. This may break the outer shell. In contrast to this, if the elastic modulus of the outer shell is decreased, it is difficult to reduce the deformation of the overall housing. In addition, as disclosed in Japanese Patent Laid-Open No. 2013-257198, when a shock absorber is attached to the outer surface of the housing, the dropping impact of the radiation imaging apparatus is transmitted to the housing through the shock absorber. This may distort or deform the overall housing. As described above, it is difficult for the existing methods to reduce both the breakage and deformation of the housing.